drivers/dma/tegra20-apb-dma.c

   1 /*
   2  * DMA driver for Nvidia's Tegra20 APB DMA controller.
   3  *
   4  * Copyright (c) 2012-2013, NVIDIA CORPORATION.  All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 #include <linux/bitops.h>
  20 #include <linux/clk.h>
  21 #include <linux/delay.h>
  22 #include <linux/dmaengine.h>
  23 #include <linux/dma-mapping.h>
  24 #include <linux/err.h>
  25 #include <linux/init.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/io.h>
  28 #include <linux/mm.h>
  29 #include <linux/module.h>
  30 #include <linux/of.h>
  31 #include <linux/of_device.h>
  32 #include <linux/of_dma.h>
  33 #include <linux/platform_device.h>
  34 #include <linux/pm.h>
  35 #include <linux/pm_runtime.h>
  36 #include <linux/reset.h>
  37 #include <linux/slab.h>
  38
  39 #include "dmaengine.h"
  40
  41 #define TEGRA_APBDMA_GENERAL                    0x0
  42 #define TEGRA_APBDMA_GENERAL_ENABLE             BIT(31)
  43
  44 #define TEGRA_APBDMA_CONTROL                    0x010
  45 #define TEGRA_APBDMA_IRQ_MASK                   0x01c
  46 #define TEGRA_APBDMA_IRQ_MASK_SET               0x020
  47
  48 /* CSR register */
  49 #define TEGRA_APBDMA_CHAN_CSR                   0x00
  50 #define TEGRA_APBDMA_CSR_ENB                    BIT(31)
  51 #define TEGRA_APBDMA_CSR_IE_EOC                 BIT(30)
  52 #define TEGRA_APBDMA_CSR_HOLD                   BIT(29)
  53 #define TEGRA_APBDMA_CSR_DIR                    BIT(28)
  54 #define TEGRA_APBDMA_CSR_ONCE                   BIT(27)
  55 #define TEGRA_APBDMA_CSR_FLOW                   BIT(21)
  56 #define TEGRA_APBDMA_CSR_REQ_SEL_SHIFT          16
  57 #define TEGRA_APBDMA_CSR_REQ_SEL_MASK           0x1F
  58 #define TEGRA_APBDMA_CSR_WCOUNT_MASK            0xFFFC
  59
  60 /* STATUS register */
  61 #define TEGRA_APBDMA_CHAN_STATUS                0x004
  62 #define TEGRA_APBDMA_STATUS_BUSY                BIT(31)
  63 #define TEGRA_APBDMA_STATUS_ISE_EOC             BIT(30)
  64 #define TEGRA_APBDMA_STATUS_HALT                BIT(29)
  65 #define TEGRA_APBDMA_STATUS_PING_PONG           BIT(28)
  66 #define TEGRA_APBDMA_STATUS_COUNT_SHIFT         2
  67 #define TEGRA_APBDMA_STATUS_COUNT_MASK          0xFFFC
  68
  69 #define TEGRA_APBDMA_CHAN_CSRE                  0x00C
  70 #define TEGRA_APBDMA_CHAN_CSRE_PAUSE            (1 << 31)
  71
  72 /* AHB memory address */
  73 #define TEGRA_APBDMA_CHAN_AHBPTR                0x010
  74
  75 /* AHB sequence register */
  76 #define TEGRA_APBDMA_CHAN_AHBSEQ                0x14
  77 #define TEGRA_APBDMA_AHBSEQ_INTR_ENB            BIT(31)
  78 #define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_8         (0 << 28)
  79 #define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_16        (1 << 28)
  80 #define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32        (2 << 28)
  81 #define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_64        (3 << 28)
  82 #define TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_128       (4 << 28)
  83 #define TEGRA_APBDMA_AHBSEQ_DATA_SWAP           BIT(27)
  84 #define TEGRA_APBDMA_AHBSEQ_BURST_1             (4 << 24)
  85 #define TEGRA_APBDMA_AHBSEQ_BURST_4             (5 << 24)
  86 #define TEGRA_APBDMA_AHBSEQ_BURST_8             (6 << 24)
  87 #define TEGRA_APBDMA_AHBSEQ_DBL_BUF             BIT(19)
  88 #define TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT          16
  89 #define TEGRA_APBDMA_AHBSEQ_WRAP_NONE           0
  90
  91 /* APB address */
  92 #define TEGRA_APBDMA_CHAN_APBPTR                0x018
  93
  94 /* APB sequence register */
  95 #define TEGRA_APBDMA_CHAN_APBSEQ                0x01c
  96 #define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8         (0 << 28)
  97 #define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16        (1 << 28)
  98 #define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32        (2 << 28)
  99 #define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64        (3 << 28)
 100 #define TEGRA_APBDMA_APBSEQ_BUS_WIDTH_128       (4 << 28)
 101 #define TEGRA_APBDMA_APBSEQ_DATA_SWAP           BIT(27)
 102 #define TEGRA_APBDMA_APBSEQ_WRAP_WORD_1         (1 << 16)
 103
 104 /* Tegra148 specific registers */
 105 #define TEGRA_APBDMA_CHAN_WCOUNT                0x20
 106
 107 #define TEGRA_APBDMA_CHAN_WORD_TRANSFER         0x24
 108
 109 /*
 110  * If any burst is in flight and DMA paused then this is the time to complete
 111  * on-flight burst and update DMA status register.
 112  */
 113 #define TEGRA_APBDMA_BURST_COMPLETE_TIME        20
 114
 115 /* Channel base address offset from APBDMA base address */
 116 #define TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET    0x1000
 117
 118 #define TEGRA_APBDMA_SLAVE_ID_INVALID   (TEGRA_APBDMA_CSR_REQ_SEL_MASK + 1)
 119
 120 struct tegra_dma;
 121
 122 /*
 123  * tegra_dma_chip_data Tegra chip specific DMA data
 124  * @nr_channels: Number of channels available in the controller.
 125  * @channel_reg_size: Channel register size/stride.
 126  * @max_dma_count: Maximum DMA transfer count supported by DMA controller.
 127  * @support_channel_pause: Support channel wise pause of dma.
 128  * @support_separate_wcount_reg: Support separate word count register.
 129  */
 130 struct tegra_dma_chip_data {
 131         int nr_channels;
 132         int channel_reg_size;
 133         int max_dma_count;
 134         bool support_channel_pause;
 135         bool support_separate_wcount_reg;
 136 };
 137
 138 /* DMA channel registers */
 139 struct tegra_dma_channel_regs {
 140         unsigned long   csr;
 141         unsigned long   ahb_ptr;
 142         unsigned long   apb_ptr;
 143         unsigned long   ahb_seq;
 144         unsigned long   apb_seq;
 145         unsigned long   wcount;
 146 };
 147
 148 /*
 149  * tegra_dma_sg_req: Dma request details to configure hardware. This
 150  * contains the details for one transfer to configure DMA hw.
 151  * The client's request for data transfer can be broken into multiple
 152  * sub-transfer as per requester details and hw support.
 153  * This sub transfer get added in the list of transfer and point to Tegra
 154  * DMA descriptor which manages the transfer details.
 155  */
 156 struct tegra_dma_sg_req {
 157         struct tegra_dma_channel_regs   ch_regs;
 158         int                             req_len;
 159         bool                            configured;
 160         bool                            last_sg;
 161         struct list_head                node;
 162         struct tegra_dma_desc           *dma_desc;
 163 };
 164
 165 /*
 166  * tegra_dma_desc: Tegra DMA descriptors which manages the client requests.
 167  * This descriptor keep track of transfer status, callbacks and request
 168  * counts etc.
 169  */
 170 struct tegra_dma_desc {
 171         struct dma_async_tx_descriptor  txd;
 172         int                             bytes_requested;
 173         int                             bytes_transferred;
 174         enum dma_status                 dma_status;
 175         struct list_head                node;
 176         struct list_head                tx_list;
 177         struct list_head                cb_node;
 178         int                             cb_count;
 179 };
 180
 181 struct tegra_dma_channel;
 182
 183 typedef void (*dma_isr_handler)(struct tegra_dma_channel *tdc,
 184                                 bool to_terminate);
 185
 186 /* tegra_dma_channel: Channel specific information */
 187 struct tegra_dma_channel {
 188         struct dma_chan         dma_chan;
 189         char                    name[30];
 190         bool                    config_init;
 191         int                     id;
 192         int                     irq;
 193         void __iomem            *chan_addr;
 194         spinlock_t              lock;
 195         bool                    busy;
 196         struct tegra_dma        *tdma;
 197         bool                    cyclic;
 198
 199         /* Different lists for managing the requests */
 200         struct list_head        free_sg_req;
 201         struct list_head        pending_sg_req;
 202         struct list_head        free_dma_desc;
 203         struct list_head        cb_desc;
 204
 205         /* ISR handler and tasklet for bottom half of isr handling */
 206         dma_isr_handler         isr_handler;
 207         struct tasklet_struct   tasklet;
 208
 209         /* Channel-slave specific configuration */
 210         unsigned int slave_id;
 211         struct dma_slave_config dma_sconfig;
 212         struct tegra_dma_channel_regs   channel_reg;
 213 };
 214
 215 /* tegra_dma: Tegra DMA specific information */
 216 struct tegra_dma {
 217         struct dma_device               dma_dev;
 218         struct device                   *dev;
 219         struct clk                      *dma_clk;
 220         struct reset_control            *rst;
 221         spinlock_t                      global_lock;
 222         void __iomem                    *base_addr;
 223         const struct tegra_dma_chip_data *chip_data;
 224
 225         /*
 226          * Counter for managing global pausing of the DMA controller.
 227          * Only applicable for devices that don't support individual
 228          * channel pausing.
 229          */
 230         u32                             global_pause_count;
 231
 232         /* Some register need to be cache before suspend */
 233         u32                             reg_gen;
 234
 235         /* Last member of the structure */
 236         struct tegra_dma_channel channels[0];
 237 };
 238
 239 static inline void tdma_write(struct tegra_dma *tdma, u32 reg, u32 val)
 240 {
 241         writel(val, tdma->base_addr + reg);
 242 }
 243
 244 static inline u32 tdma_read(struct tegra_dma *tdma, u32 reg)
 245 {
 246         return readl(tdma->base_addr + reg);
 247 }
 248
 249 static inline void tdc_write(struct tegra_dma_channel *tdc,
 250                 u32 reg, u32 val)
 251 {
 252         writel(val, tdc->chan_addr + reg);
 253 }
 254
 255 static inline u32 tdc_read(struct tegra_dma_channel *tdc, u32 reg)
 256 {
 257         return readl(tdc->chan_addr + reg);
 258 }
 259
 260 static inline struct tegra_dma_channel *to_tegra_dma_chan(struct dma_chan *dc)
 261 {
 262         return container_of(dc, struct tegra_dma_channel, dma_chan);
 263 }
 264
 265 static inline struct tegra_dma_desc *txd_to_tegra_dma_desc(
 266                 struct dma_async_tx_descriptor *td)
 267 {
 268         return container_of(td, struct tegra_dma_desc, txd);
 269 }
 270
 271 static inline struct device *tdc2dev(struct tegra_dma_channel *tdc)
 272 {
 273         return &tdc->dma_chan.dev->device;
 274 }
 275
 276 static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *tx);
 277 static int tegra_dma_runtime_suspend(struct device *dev);
 278 static int tegra_dma_runtime_resume(struct device *dev);
 279
 280 /* Get DMA desc from free list, if not there then allocate it.  */
 281 static struct tegra_dma_desc *tegra_dma_desc_get(
 282                 struct tegra_dma_channel *tdc)
 283 {
 284         struct tegra_dma_desc *dma_desc;
 285         unsigned long flags;
 286
 287         spin_lock_irqsave(&tdc->lock, flags);
 288
 289         /* Do not allocate if desc are waiting for ack */
 290         list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
 291                 if (async_tx_test_ack(&dma_desc->txd)) {
 292                         list_del(&dma_desc->node);
 293                         spin_unlock_irqrestore(&tdc->lock, flags);
 294                         dma_desc->txd.flags = 0;
 295                         return dma_desc;
 296                 }
 297         }
 298
 299         spin_unlock_irqrestore(&tdc->lock, flags);
 300
 301         /* Allocate DMA desc */
 302         dma_desc = kzalloc(sizeof(*dma_desc), GFP_NOWAIT);
 303         if (!dma_desc) {
 304                 dev_err(tdc2dev(tdc), "dma_desc alloc failed\n");
 305                 return NULL;
 306         }
 307
 308         dma_async_tx_descriptor_init(&dma_desc->txd, &tdc->dma_chan);
 309         dma_desc->txd.tx_submit = tegra_dma_tx_submit;
 310         dma_desc->txd.flags = 0;
 311         return dma_desc;
 312 }
 313
 314 static void tegra_dma_desc_put(struct tegra_dma_channel *tdc,
 315                 struct tegra_dma_desc *dma_desc)
 316 {
 317         unsigned long flags;
 318
 319         spin_lock_irqsave(&tdc->lock, flags);
 320         if (!list_empty(&dma_desc->tx_list))
 321                 list_splice_init(&dma_desc->tx_list, &tdc->free_sg_req);
 322         list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 323         spin_unlock_irqrestore(&tdc->lock, flags);
 324 }
 325
 326 static struct tegra_dma_sg_req *tegra_dma_sg_req_get(
 327                 struct tegra_dma_channel *tdc)
 328 {
 329         struct tegra_dma_sg_req *sg_req = NULL;
 330         unsigned long flags;
 331
 332         spin_lock_irqsave(&tdc->lock, flags);
 333         if (!list_empty(&tdc->free_sg_req)) {
 334                 sg_req = list_first_entry(&tdc->free_sg_req,
 335                                         typeof(*sg_req), node);
 336                 list_del(&sg_req->node);
 337                 spin_unlock_irqrestore(&tdc->lock, flags);
 338                 return sg_req;
 339         }
 340         spin_unlock_irqrestore(&tdc->lock, flags);
 341
 342         sg_req = kzalloc(sizeof(struct tegra_dma_sg_req), GFP_NOWAIT);
 343         if (!sg_req)
 344                 dev_err(tdc2dev(tdc), "sg_req alloc failed\n");
 345         return sg_req;
 346 }
 347
 348 static int tegra_dma_slave_config(struct dma_chan *dc,
 349                 struct dma_slave_config *sconfig)
 350 {
 351         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 352
 353         if (!list_empty(&tdc->pending_sg_req)) {
 354                 dev_err(tdc2dev(tdc), "Configuration not allowed\n");
 355                 return -EBUSY;
 356         }
 357
 358         memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
 359         if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID) {
 360                 if (sconfig->slave_id > TEGRA_APBDMA_CSR_REQ_SEL_MASK)
 361                         return -EINVAL;
 362                 tdc->slave_id = sconfig->slave_id;
 363         }
 364         tdc->config_init = true;
 365         return 0;
 366 }
 367
 368 static void tegra_dma_global_pause(struct tegra_dma_channel *tdc,
 369         bool wait_for_burst_complete)
 370 {
 371         struct tegra_dma *tdma = tdc->tdma;
 372
 373         spin_lock(&tdma->global_lock);
 374
 375         if (tdc->tdma->global_pause_count == 0) {
 376                 tdma_write(tdma, TEGRA_APBDMA_GENERAL, 0);
 377                 if (wait_for_burst_complete)
 378                         udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 379         }
 380
 381         tdc->tdma->global_pause_count++;
 382
 383         spin_unlock(&tdma->global_lock);
 384 }
 385
 386 static void tegra_dma_global_resume(struct tegra_dma_channel *tdc)
 387 {
 388         struct tegra_dma *tdma = tdc->tdma;
 389
 390         spin_lock(&tdma->global_lock);
 391
 392         if (WARN_ON(tdc->tdma->global_pause_count == 0))
 393                 goto out;
 394
 395         if (--tdc->tdma->global_pause_count == 0)
 396                 tdma_write(tdma, TEGRA_APBDMA_GENERAL,
 397                            TEGRA_APBDMA_GENERAL_ENABLE);
 398
 399 out:
 400         spin_unlock(&tdma->global_lock);
 401 }
 402
 403 static void tegra_dma_pause(struct tegra_dma_channel *tdc,
 404         bool wait_for_burst_complete)
 405 {
 406         struct tegra_dma *tdma = tdc->tdma;
 407
 408         if (tdma->chip_data->support_channel_pause) {
 409                 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE,
 410                                 TEGRA_APBDMA_CHAN_CSRE_PAUSE);
 411                 if (wait_for_burst_complete)
 412                         udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 413         } else {
 414                 tegra_dma_global_pause(tdc, wait_for_burst_complete);
 415         }
 416 }
 417
 418 static void tegra_dma_resume(struct tegra_dma_channel *tdc)
 419 {
 420         struct tegra_dma *tdma = tdc->tdma;
 421
 422         if (tdma->chip_data->support_channel_pause) {
 423                 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSRE, 0);
 424         } else {
 425                 tegra_dma_global_resume(tdc);
 426         }
 427 }
 428
 429 static void tegra_dma_stop(struct tegra_dma_channel *tdc)
 430 {
 431         u32 csr;
 432         u32 status;
 433
 434         /* Disable interrupts */
 435         csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
 436         csr &= ~TEGRA_APBDMA_CSR_IE_EOC;
 437         tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
 438
 439         /* Disable DMA */
 440         csr &= ~TEGRA_APBDMA_CSR_ENB;
 441         tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, csr);
 442
 443         /* Clear interrupt status if it is there */
 444         status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 445         if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 446                 dev_dbg(tdc2dev(tdc), "%s():clearing interrupt\n", __func__);
 447                 tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
 448         }
 449         tdc->busy = false;
 450 }
 451
 452 static void tegra_dma_start(struct tegra_dma_channel *tdc,
 453                 struct tegra_dma_sg_req *sg_req)
 454 {
 455         struct tegra_dma_channel_regs *ch_regs = &sg_req->ch_regs;
 456
 457         tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR, ch_regs->csr);
 458         tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_regs->apb_seq);
 459         tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_regs->apb_ptr);
 460         tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_regs->ahb_seq);
 461         tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_regs->ahb_ptr);
 462         if (tdc->tdma->chip_data->support_separate_wcount_reg)
 463                 tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT, ch_regs->wcount);
 464
 465         /* Start DMA */
 466         tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
 467                                 ch_regs->csr | TEGRA_APBDMA_CSR_ENB);
 468 }
 469
 470 static void tegra_dma_configure_for_next(struct tegra_dma_channel *tdc,
 471                 struct tegra_dma_sg_req *nsg_req)
 472 {
 473         unsigned long status;
 474
 475         /*
 476          * The DMA controller reloads the new configuration for next transfer
 477          * after last burst of current transfer completes.
 478          * If there is no IEC status then this makes sure that last burst
 479          * has not be completed. There may be case that last burst is on
 480          * flight and so it can complete but because DMA is paused, it
 481          * will not generates interrupt as well as not reload the new
 482          * configuration.
 483          * If there is already IEC status then interrupt handler need to
 484          * load new configuration.
 485          */
 486         tegra_dma_pause(tdc, false);
 487         status  = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 488
 489         /*
 490          * If interrupt is pending then do nothing as the ISR will handle
 491          * the programing for new request.
 492          */
 493         if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 494                 dev_err(tdc2dev(tdc),
 495                         "Skipping new configuration as interrupt is pending\n");
 496                 tegra_dma_resume(tdc);
 497                 return;
 498         }
 499
 500         /* Safe to program new configuration */
 501         tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, nsg_req->ch_regs.apb_ptr);
 502         tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, nsg_req->ch_regs.ahb_ptr);
 503         if (tdc->tdma->chip_data->support_separate_wcount_reg)
 504                 tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
 505                                                 nsg_req->ch_regs.wcount);
 506         tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
 507                                 nsg_req->ch_regs.csr | TEGRA_APBDMA_CSR_ENB);
 508         nsg_req->configured = true;
 509
 510         tegra_dma_resume(tdc);
 511 }
 512
 513 static void tdc_start_head_req(struct tegra_dma_channel *tdc)
 514 {
 515         struct tegra_dma_sg_req *sg_req;
 516
 517         if (list_empty(&tdc->pending_sg_req))
 518                 return;
 519
 520         sg_req = list_first_entry(&tdc->pending_sg_req,
 521                                         typeof(*sg_req), node);
 522         tegra_dma_start(tdc, sg_req);
 523         sg_req->configured = true;
 524         tdc->busy = true;
 525 }
 526
 527 static void tdc_configure_next_head_desc(struct tegra_dma_channel *tdc)
 528 {
 529         struct tegra_dma_sg_req *hsgreq;
 530         struct tegra_dma_sg_req *hnsgreq;
 531
 532         if (list_empty(&tdc->pending_sg_req))
 533                 return;
 534
 535         hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
 536         if (!list_is_last(&hsgreq->node, &tdc->pending_sg_req)) {
 537                 hnsgreq = list_first_entry(&hsgreq->node,
 538                                         typeof(*hnsgreq), node);
 539                 tegra_dma_configure_for_next(tdc, hnsgreq);
 540         }
 541 }
 542
 543 static inline int get_current_xferred_count(struct tegra_dma_channel *tdc,
 544         struct tegra_dma_sg_req *sg_req, unsigned long status)
 545 {
 546         return sg_req->req_len - (status & TEGRA_APBDMA_STATUS_COUNT_MASK) - 4;
 547 }
 548
 549 static void tegra_dma_abort_all(struct tegra_dma_channel *tdc)
 550 {
 551         struct tegra_dma_sg_req *sgreq;
 552         struct tegra_dma_desc *dma_desc;
 553
 554         while (!list_empty(&tdc->pending_sg_req)) {
 555                 sgreq = list_first_entry(&tdc->pending_sg_req,
 556                                                 typeof(*sgreq), node);
 557                 list_move_tail(&sgreq->node, &tdc->free_sg_req);
 558                 if (sgreq->last_sg) {
 559                         dma_desc = sgreq->dma_desc;
 560                         dma_desc->dma_status = DMA_ERROR;
 561                         list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 562
 563                         /* Add in cb list if it is not there. */
 564                         if (!dma_desc->cb_count)
 565                                 list_add_tail(&dma_desc->cb_node,
 566                                                         &tdc->cb_desc);
 567                         dma_desc->cb_count++;
 568                 }
 569         }
 570         tdc->isr_handler = NULL;
 571 }
 572
 573 static bool handle_continuous_head_request(struct tegra_dma_channel *tdc,
 574                 struct tegra_dma_sg_req *last_sg_req, bool to_terminate)
 575 {
 576         struct tegra_dma_sg_req *hsgreq = NULL;
 577
 578         if (list_empty(&tdc->pending_sg_req)) {
 579                 dev_err(tdc2dev(tdc), "Dma is running without req\n");
 580                 tegra_dma_stop(tdc);
 581                 return false;
 582         }
 583
 584         /*
 585          * Check that head req on list should be in flight.
 586          * If it is not in flight then abort transfer as
 587          * looping of transfer can not continue.
 588          */
 589         hsgreq = list_first_entry(&tdc->pending_sg_req, typeof(*hsgreq), node);
 590         if (!hsgreq->configured) {
 591                 tegra_dma_stop(tdc);
 592                 dev_err(tdc2dev(tdc), "Error in dma transfer, aborting dma\n");
 593                 tegra_dma_abort_all(tdc);
 594                 return false;
 595         }
 596
 597         /* Configure next request */
 598         if (!to_terminate)
 599                 tdc_configure_next_head_desc(tdc);
 600         return true;
 601 }
 602
 603 static void handle_once_dma_done(struct tegra_dma_channel *tdc,
 604         bool to_terminate)
 605 {
 606         struct tegra_dma_sg_req *sgreq;
 607         struct tegra_dma_desc *dma_desc;
 608
 609         tdc->busy = false;
 610         sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
 611         dma_desc = sgreq->dma_desc;
 612         dma_desc->bytes_transferred += sgreq->req_len;
 613
 614         list_del(&sgreq->node);
 615         if (sgreq->last_sg) {
 616                 dma_desc->dma_status = DMA_COMPLETE;
 617                 dma_cookie_complete(&dma_desc->txd);
 618                 if (!dma_desc->cb_count)
 619                         list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
 620                 dma_desc->cb_count++;
 621                 list_add_tail(&dma_desc->node, &tdc->free_dma_desc);
 622         }
 623         list_add_tail(&sgreq->node, &tdc->free_sg_req);
 624
 625         /* Do not start DMA if it is going to be terminate */
 626         if (to_terminate || list_empty(&tdc->pending_sg_req))
 627                 return;
 628
 629         tdc_start_head_req(tdc);
 630 }
 631
 632 static void handle_cont_sngl_cycle_dma_done(struct tegra_dma_channel *tdc,
 633                 bool to_terminate)
 634 {
 635         struct tegra_dma_sg_req *sgreq;
 636         struct tegra_dma_desc *dma_desc;
 637         bool st;
 638
 639         sgreq = list_first_entry(&tdc->pending_sg_req, typeof(*sgreq), node);
 640         dma_desc = sgreq->dma_desc;
 641         dma_desc->bytes_transferred += sgreq->req_len;
 642
 643         /* Callback need to be call */
 644         if (!dma_desc->cb_count)
 645                 list_add_tail(&dma_desc->cb_node, &tdc->cb_desc);
 646         dma_desc->cb_count++;
 647
 648         /* If not last req then put at end of pending list */
 649         if (!list_is_last(&sgreq->node, &tdc->pending_sg_req)) {
 650                 list_move_tail(&sgreq->node, &tdc->pending_sg_req);
 651                 sgreq->configured = false;
 652                 st = handle_continuous_head_request(tdc, sgreq, to_terminate);
 653                 if (!st)
 654                         dma_desc->dma_status = DMA_ERROR;
 655         }
 656 }
 657
 658 static void tegra_dma_tasklet(unsigned long data)
 659 {
 660         struct tegra_dma_channel *tdc = (struct tegra_dma_channel *)data;
 661         dma_async_tx_callback callback = NULL;
 662         void *callback_param = NULL;
 663         struct tegra_dma_desc *dma_desc;
 664         unsigned long flags;
 665         int cb_count;
 666
 667         spin_lock_irqsave(&tdc->lock, flags);
 668         while (!list_empty(&tdc->cb_desc)) {
 669                 dma_desc  = list_first_entry(&tdc->cb_desc,
 670                                         typeof(*dma_desc), cb_node);
 671                 list_del(&dma_desc->cb_node);
 672                 callback = dma_desc->txd.callback;
 673                 callback_param = dma_desc->txd.callback_param;
 674                 cb_count = dma_desc->cb_count;
 675                 dma_desc->cb_count = 0;
 676                 spin_unlock_irqrestore(&tdc->lock, flags);
 677                 while (cb_count-- && callback)
 678                         callback(callback_param);
 679                 spin_lock_irqsave(&tdc->lock, flags);
 680         }
 681         spin_unlock_irqrestore(&tdc->lock, flags);
 682 }
 683
 684 static irqreturn_t tegra_dma_isr(int irq, void *dev_id)
 685 {
 686         struct tegra_dma_channel *tdc = dev_id;
 687         unsigned long status;
 688         unsigned long flags;
 689
 690         spin_lock_irqsave(&tdc->lock, flags);
 691
 692         status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 693         if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 694                 tdc_write(tdc, TEGRA_APBDMA_CHAN_STATUS, status);
 695                 tdc->isr_handler(tdc, false);
 696                 tasklet_schedule(&tdc->tasklet);
 697                 spin_unlock_irqrestore(&tdc->lock, flags);
 698                 return IRQ_HANDLED;
 699         }
 700
 701         spin_unlock_irqrestore(&tdc->lock, flags);
 702         dev_info(tdc2dev(tdc),
 703                 "Interrupt already served status 0x%08lx\n", status);
 704         return IRQ_NONE;
 705 }
 706
 707 static dma_cookie_t tegra_dma_tx_submit(struct dma_async_tx_descriptor *txd)
 708 {
 709         struct tegra_dma_desc *dma_desc = txd_to_tegra_dma_desc(txd);
 710         struct tegra_dma_channel *tdc = to_tegra_dma_chan(txd->chan);
 711         unsigned long flags;
 712         dma_cookie_t cookie;
 713
 714         spin_lock_irqsave(&tdc->lock, flags);
 715         dma_desc->dma_status = DMA_IN_PROGRESS;
 716         cookie = dma_cookie_assign(&dma_desc->txd);
 717         list_splice_tail_init(&dma_desc->tx_list, &tdc->pending_sg_req);
 718         spin_unlock_irqrestore(&tdc->lock, flags);
 719         return cookie;
 720 }
 721
 722 static void tegra_dma_issue_pending(struct dma_chan *dc)
 723 {
 724         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 725         unsigned long flags;
 726
 727         spin_lock_irqsave(&tdc->lock, flags);
 728         if (list_empty(&tdc->pending_sg_req)) {
 729                 dev_err(tdc2dev(tdc), "No DMA request\n");
 730                 goto end;
 731         }
 732         if (!tdc->busy) {
 733                 tdc_start_head_req(tdc);
 734
 735                 /* Continuous single mode: Configure next req */
 736                 if (tdc->cyclic) {
 737                         /*
 738                          * Wait for 1 burst time for configure DMA for
 739                          * next transfer.
 740                          */
 741                         udelay(TEGRA_APBDMA_BURST_COMPLETE_TIME);
 742                         tdc_configure_next_head_desc(tdc);
 743                 }
 744         }
 745 end:
 746         spin_unlock_irqrestore(&tdc->lock, flags);
 747 }
 748
 749 static int tegra_dma_terminate_all(struct dma_chan *dc)
 750 {
 751         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 752         struct tegra_dma_sg_req *sgreq;
 753         struct tegra_dma_desc *dma_desc;
 754         unsigned long flags;
 755         unsigned long status;
 756         unsigned long wcount;
 757         bool was_busy;
 758
 759         spin_lock_irqsave(&tdc->lock, flags);
 760         if (list_empty(&tdc->pending_sg_req)) {
 761                 spin_unlock_irqrestore(&tdc->lock, flags);
 762                 return 0;
 763         }
 764
 765         if (!tdc->busy)
 766                 goto skip_dma_stop;
 767
 768         /* Pause DMA before checking the queue status */
 769         tegra_dma_pause(tdc, true);
 770
 771         status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 772         if (status & TEGRA_APBDMA_STATUS_ISE_EOC) {
 773                 dev_dbg(tdc2dev(tdc), "%s():handling isr\n", __func__);
 774                 tdc->isr_handler(tdc, true);
 775                 status = tdc_read(tdc, TEGRA_APBDMA_CHAN_STATUS);
 776         }
 777         if (tdc->tdma->chip_data->support_separate_wcount_reg)
 778                 wcount = tdc_read(tdc, TEGRA_APBDMA_CHAN_WORD_TRANSFER);
 779         else
 780                 wcount = status;
 781
 782         was_busy = tdc->busy;
 783         tegra_dma_stop(tdc);
 784
 785         if (!list_empty(&tdc->pending_sg_req) && was_busy) {
 786                 sgreq = list_first_entry(&tdc->pending_sg_req,
 787                                         typeof(*sgreq), node);
 788                 sgreq->dma_desc->bytes_transferred +=
 789                                 get_current_xferred_count(tdc, sgreq, wcount);
 790         }
 791         tegra_dma_resume(tdc);
 792
 793 skip_dma_stop:
 794         tegra_dma_abort_all(tdc);
 795
 796         while (!list_empty(&tdc->cb_desc)) {
 797                 dma_desc  = list_first_entry(&tdc->cb_desc,
 798                                         typeof(*dma_desc), cb_node);
 799                 list_del(&dma_desc->cb_node);
 800                 dma_desc->cb_count = 0;
 801         }
 802         spin_unlock_irqrestore(&tdc->lock, flags);
 803         return 0;
 804 }
 805
 806 static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
 807         dma_cookie_t cookie, struct dma_tx_state *txstate)
 808 {
 809         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 810         struct tegra_dma_desc *dma_desc;
 811         struct tegra_dma_sg_req *sg_req;
 812         enum dma_status ret;
 813         unsigned long flags;
 814         unsigned int residual;
 815
 816         ret = dma_cookie_status(dc, cookie, txstate);
 817         if (ret == DMA_COMPLETE)
 818                 return ret;
 819
 820         spin_lock_irqsave(&tdc->lock, flags);
 821
 822         /* Check on wait_ack desc status */
 823         list_for_each_entry(dma_desc, &tdc->free_dma_desc, node) {
 824                 if (dma_desc->txd.cookie == cookie) {
 825                         residual =  dma_desc->bytes_requested -
 826                                         (dma_desc->bytes_transferred %
 827                                                 dma_desc->bytes_requested);
 828                         dma_set_residue(txstate, residual);
 829                         ret = dma_desc->dma_status;
 830                         spin_unlock_irqrestore(&tdc->lock, flags);
 831                         return ret;
 832                 }
 833         }
 834
 835         /* Check in pending list */
 836         list_for_each_entry(sg_req, &tdc->pending_sg_req, node) {
 837                 dma_desc = sg_req->dma_desc;
 838                 if (dma_desc->txd.cookie == cookie) {
 839                         residual =  dma_desc->bytes_requested -
 840                                         (dma_desc->bytes_transferred %
 841                                                 dma_desc->bytes_requested);
 842                         dma_set_residue(txstate, residual);
 843                         ret = dma_desc->dma_status;
 844                         spin_unlock_irqrestore(&tdc->lock, flags);
 845                         return ret;
 846                 }
 847         }
 848
 849         dev_dbg(tdc2dev(tdc), "cookie %d does not found\n", cookie);
 850         spin_unlock_irqrestore(&tdc->lock, flags);
 851         return ret;
 852 }
 853
 854 static inline int get_bus_width(struct tegra_dma_channel *tdc,
 855                 enum dma_slave_buswidth slave_bw)
 856 {
 857         switch (slave_bw) {
 858         case DMA_SLAVE_BUSWIDTH_1_BYTE:
 859                 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_8;
 860         case DMA_SLAVE_BUSWIDTH_2_BYTES:
 861                 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_16;
 862         case DMA_SLAVE_BUSWIDTH_4_BYTES:
 863                 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
 864         case DMA_SLAVE_BUSWIDTH_8_BYTES:
 865                 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_64;
 866         default:
 867                 dev_warn(tdc2dev(tdc),
 868                         "slave bw is not supported, using 32bits\n");
 869                 return TEGRA_APBDMA_APBSEQ_BUS_WIDTH_32;
 870         }
 871 }
 872
 873 static inline int get_burst_size(struct tegra_dma_channel *tdc,
 874         u32 burst_size, enum dma_slave_buswidth slave_bw, int len)
 875 {
 876         int burst_byte;
 877         int burst_ahb_width;
 878
 879         /*
 880          * burst_size from client is in terms of the bus_width.
 881          * convert them into AHB memory width which is 4 byte.
 882          */
 883         burst_byte = burst_size * slave_bw;
 884         burst_ahb_width = burst_byte / 4;
 885
 886         /* If burst size is 0 then calculate the burst size based on length */
 887         if (!burst_ahb_width) {
 888                 if (len & 0xF)
 889                         return TEGRA_APBDMA_AHBSEQ_BURST_1;
 890                 else if ((len >> 4) & 0x1)
 891                         return TEGRA_APBDMA_AHBSEQ_BURST_4;
 892                 else
 893                         return TEGRA_APBDMA_AHBSEQ_BURST_8;
 894         }
 895         if (burst_ahb_width < 4)
 896                 return TEGRA_APBDMA_AHBSEQ_BURST_1;
 897         else if (burst_ahb_width < 8)
 898                 return TEGRA_APBDMA_AHBSEQ_BURST_4;
 899         else
 900                 return TEGRA_APBDMA_AHBSEQ_BURST_8;
 901 }
 902
 903 static int get_transfer_param(struct tegra_dma_channel *tdc,
 904         enum dma_transfer_direction direction, unsigned long *apb_addr,
 905         unsigned long *apb_seq, unsigned long *csr, unsigned int *burst_size,
 906         enum dma_slave_buswidth *slave_bw)
 907 {
 908
 909         switch (direction) {
 910         case DMA_MEM_TO_DEV:
 911                 *apb_addr = tdc->dma_sconfig.dst_addr;
 912                 *apb_seq = get_bus_width(tdc, tdc->dma_sconfig.dst_addr_width);
 913                 *burst_size = tdc->dma_sconfig.dst_maxburst;
 914                 *slave_bw = tdc->dma_sconfig.dst_addr_width;
 915                 *csr = TEGRA_APBDMA_CSR_DIR;
 916                 return 0;
 917
 918         case DMA_DEV_TO_MEM:
 919                 *apb_addr = tdc->dma_sconfig.src_addr;
 920                 *apb_seq = get_bus_width(tdc, tdc->dma_sconfig.src_addr_width);
 921                 *burst_size = tdc->dma_sconfig.src_maxburst;
 922                 *slave_bw = tdc->dma_sconfig.src_addr_width;
 923                 *csr = 0;
 924                 return 0;
 925
 926         default:
 927                 dev_err(tdc2dev(tdc), "Dma direction is not supported\n");
 928                 return -EINVAL;
 929         }
 930         return -EINVAL;
 931 }
 932
 933 static void tegra_dma_prep_wcount(struct tegra_dma_channel *tdc,
 934         struct tegra_dma_channel_regs *ch_regs, u32 len)
 935 {
 936         u32 len_field = (len - 4) & 0xFFFC;
 937
 938         if (tdc->tdma->chip_data->support_separate_wcount_reg)
 939                 ch_regs->wcount = len_field;
 940         else
 941                 ch_regs->csr |= len_field;
 942 }
 943
 944 static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
 945         struct dma_chan *dc, struct scatterlist *sgl, unsigned int sg_len,
 946         enum dma_transfer_direction direction, unsigned long flags,
 947         void *context)
 948 {
 949         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
 950         struct tegra_dma_desc *dma_desc;
 951         unsigned int        i;
 952         struct scatterlist      *sg;
 953         unsigned long csr, ahb_seq, apb_ptr, apb_seq;
 954         struct list_head req_list;
 955         struct tegra_dma_sg_req  *sg_req = NULL;
 956         u32 burst_size;
 957         enum dma_slave_buswidth slave_bw;
 958
 959         if (!tdc->config_init) {
 960                 dev_err(tdc2dev(tdc), "dma channel is not configured\n");
 961                 return NULL;
 962         }
 963         if (sg_len < 1) {
 964                 dev_err(tdc2dev(tdc), "Invalid segment length %d\n", sg_len);
 965                 return NULL;
 966         }
 967
 968         if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
 969                                 &burst_size, &slave_bw) < 0)
 970                 return NULL;
 971
 972         INIT_LIST_HEAD(&req_list);
 973
 974         ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
 975         ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
 976                                         TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
 977         ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
 978
 979         csr |= TEGRA_APBDMA_CSR_ONCE | TEGRA_APBDMA_CSR_FLOW;
 980         csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
 981         if (flags & DMA_PREP_INTERRUPT)
 982                 csr |= TEGRA_APBDMA_CSR_IE_EOC;
 983
 984         apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
 985
 986         dma_desc = tegra_dma_desc_get(tdc);
 987         if (!dma_desc) {
 988                 dev_err(tdc2dev(tdc), "Dma descriptors not available\n");
 989                 return NULL;
 990         }
 991         INIT_LIST_HEAD(&dma_desc->tx_list);
 992         INIT_LIST_HEAD(&dma_desc->cb_node);
 993         dma_desc->cb_count = 0;
 994         dma_desc->bytes_requested = 0;
 995         dma_desc->bytes_transferred = 0;
 996         dma_desc->dma_status = DMA_IN_PROGRESS;
 997
 998         /* Make transfer requests */
 999         for_each_sg(sgl, sg, sg_len, i) {
1000                 u32 len, mem;
1001
1002                 mem = sg_dma_address(sg);
1003                 len = sg_dma_len(sg);
1004
1005                 if ((len & 3) || (mem & 3) ||
1006                                 (len > tdc->tdma->chip_data->max_dma_count)) {
1007                         dev_err(tdc2dev(tdc),
1008                                 "Dma length/memory address is not supported\n");
1009                         tegra_dma_desc_put(tdc, dma_desc);
1010                         return NULL;
1011                 }
1012
1013                 sg_req = tegra_dma_sg_req_get(tdc);
1014                 if (!sg_req) {
1015                         dev_err(tdc2dev(tdc), "Dma sg-req not available\n");
1016                         tegra_dma_desc_put(tdc, dma_desc);
1017                         return NULL;
1018                 }
1019
1020                 ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
1021                 dma_desc->bytes_requested += len;
1022
1023                 sg_req->ch_regs.apb_ptr = apb_ptr;
1024                 sg_req->ch_regs.ahb_ptr = mem;
1025                 sg_req->ch_regs.csr = csr;
1026                 tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
1027                 sg_req->ch_regs.apb_seq = apb_seq;
1028                 sg_req->ch_regs.ahb_seq = ahb_seq;
1029                 sg_req->configured = false;
1030                 sg_req->last_sg = false;
1031                 sg_req->dma_desc = dma_desc;
1032                 sg_req->req_len = len;
1033
1034                 list_add_tail(&sg_req->node, &dma_desc->tx_list);
1035         }
1036         sg_req->last_sg = true;
1037         if (flags & DMA_CTRL_ACK)
1038                 dma_desc->txd.flags = DMA_CTRL_ACK;
1039
1040         /*
1041          * Make sure that mode should not be conflicting with currently
1042          * configured mode.
1043          */
1044         if (!tdc->isr_handler) {
1045                 tdc->isr_handler = handle_once_dma_done;
1046                 tdc->cyclic = false;
1047         } else {
1048                 if (tdc->cyclic) {
1049                         dev_err(tdc2dev(tdc), "DMA configured in cyclic mode\n");
1050                         tegra_dma_desc_put(tdc, dma_desc);
1051                         return NULL;
1052                 }
1053         }
1054
1055         return &dma_desc->txd;
1056 }
1057
1058 static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
1059         struct dma_chan *dc, dma_addr_t buf_addr, size_t buf_len,
1060         size_t period_len, enum dma_transfer_direction direction,
1061         unsigned long flags)
1062 {
1063         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1064         struct tegra_dma_desc *dma_desc = NULL;
1065         struct tegra_dma_sg_req  *sg_req = NULL;
1066         unsigned long csr, ahb_seq, apb_ptr, apb_seq;
1067         int len;
1068         size_t remain_len;
1069         dma_addr_t mem = buf_addr;
1070         u32 burst_size;
1071         enum dma_slave_buswidth slave_bw;
1072
1073         if (!buf_len || !period_len) {
1074                 dev_err(tdc2dev(tdc), "Invalid buffer/period len\n");
1075                 return NULL;
1076         }
1077
1078         if (!tdc->config_init) {
1079                 dev_err(tdc2dev(tdc), "DMA slave is not configured\n");
1080                 return NULL;
1081         }
1082
1083         /*
1084          * We allow to take more number of requests till DMA is
1085          * not started. The driver will loop over all requests.
1086          * Once DMA is started then new requests can be queued only after
1087          * terminating the DMA.
1088          */
1089         if (tdc->busy) {
1090                 dev_err(tdc2dev(tdc), "Request not allowed when dma running\n");
1091                 return NULL;
1092         }
1093
1094         /*
1095          * We only support cycle transfer when buf_len is multiple of
1096          * period_len.
1097          */
1098         if (buf_len % period_len) {
1099                 dev_err(tdc2dev(tdc), "buf_len is not multiple of period_len\n");
1100                 return NULL;
1101         }
1102
1103         len = period_len;
1104         if ((len & 3) || (buf_addr & 3) ||
1105                         (len > tdc->tdma->chip_data->max_dma_count)) {
1106                 dev_err(tdc2dev(tdc), "Req len/mem address is not correct\n");
1107                 return NULL;
1108         }
1109
1110         if (get_transfer_param(tdc, direction, &apb_ptr, &apb_seq, &csr,
1111                                 &burst_size, &slave_bw) < 0)
1112                 return NULL;
1113
1114         ahb_seq = TEGRA_APBDMA_AHBSEQ_INTR_ENB;
1115         ahb_seq |= TEGRA_APBDMA_AHBSEQ_WRAP_NONE <<
1116                                         TEGRA_APBDMA_AHBSEQ_WRAP_SHIFT;
1117         ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
1118
1119         csr |= TEGRA_APBDMA_CSR_FLOW;
1120         if (flags & DMA_PREP_INTERRUPT)
1121                 csr |= TEGRA_APBDMA_CSR_IE_EOC;
1122         csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
1123
1124         apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
1125
1126         dma_desc = tegra_dma_desc_get(tdc);
1127         if (!dma_desc) {
1128                 dev_err(tdc2dev(tdc), "not enough descriptors available\n");
1129                 return NULL;
1130         }
1131
1132         INIT_LIST_HEAD(&dma_desc->tx_list);
1133         INIT_LIST_HEAD(&dma_desc->cb_node);
1134         dma_desc->cb_count = 0;
1135
1136         dma_desc->bytes_transferred = 0;
1137         dma_desc->bytes_requested = buf_len;
1138         remain_len = buf_len;
1139
1140         /* Split transfer equal to period size */
1141         while (remain_len) {
1142                 sg_req = tegra_dma_sg_req_get(tdc);
1143                 if (!sg_req) {
1144                         dev_err(tdc2dev(tdc), "Dma sg-req not available\n");
1145                         tegra_dma_desc_put(tdc, dma_desc);
1146                         return NULL;
1147                 }
1148
1149                 ahb_seq |= get_burst_size(tdc, burst_size, slave_bw, len);
1150                 sg_req->ch_regs.apb_ptr = apb_ptr;
1151                 sg_req->ch_regs.ahb_ptr = mem;
1152                 sg_req->ch_regs.csr = csr;
1153                 tegra_dma_prep_wcount(tdc, &sg_req->ch_regs, len);
1154                 sg_req->ch_regs.apb_seq = apb_seq;
1155                 sg_req->ch_regs.ahb_seq = ahb_seq;
1156                 sg_req->configured = false;
1157                 sg_req->last_sg = false;
1158                 sg_req->dma_desc = dma_desc;
1159                 sg_req->req_len = len;
1160
1161                 list_add_tail(&sg_req->node, &dma_desc->tx_list);
1162                 remain_len -= len;
1163                 mem += len;
1164         }
1165         sg_req->last_sg = true;
1166         if (flags & DMA_CTRL_ACK)
1167                 dma_desc->txd.flags = DMA_CTRL_ACK;
1168
1169         /*
1170          * Make sure that mode should not be conflicting with currently
1171          * configured mode.
1172          */
1173         if (!tdc->isr_handler) {
1174                 tdc->isr_handler = handle_cont_sngl_cycle_dma_done;
1175                 tdc->cyclic = true;
1176         } else {
1177                 if (!tdc->cyclic) {
1178                         dev_err(tdc2dev(tdc), "DMA configuration conflict\n");
1179                         tegra_dma_desc_put(tdc, dma_desc);
1180                         return NULL;
1181                 }
1182         }
1183
1184         return &dma_desc->txd;
1185 }
1186
1187 static int tegra_dma_alloc_chan_resources(struct dma_chan *dc)
1188 {
1189         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1190         struct tegra_dma *tdma = tdc->tdma;
1191         int ret;
1192
1193         dma_cookie_init(&tdc->dma_chan);
1194         tdc->config_init = false;
1195
1196         ret = pm_runtime_get_sync(tdma->dev);
1197         if (ret < 0)
1198                 return ret;
1199
1200         return 0;
1201 }
1202
1203 static void tegra_dma_free_chan_resources(struct dma_chan *dc)
1204 {
1205         struct tegra_dma_channel *tdc = to_tegra_dma_chan(dc);
1206         struct tegra_dma *tdma = tdc->tdma;
1207
1208         struct tegra_dma_desc *dma_desc;
1209         struct tegra_dma_sg_req *sg_req;
1210         struct list_head dma_desc_list;
1211         struct list_head sg_req_list;
1212         unsigned long flags;
1213
1214         INIT_LIST_HEAD(&dma_desc_list);
1215         INIT_LIST_HEAD(&sg_req_list);
1216
1217         dev_dbg(tdc2dev(tdc), "Freeing channel %d\n", tdc->id);
1218
1219         if (tdc->busy)
1220                 tegra_dma_terminate_all(dc);
1221
1222         spin_lock_irqsave(&tdc->lock, flags);
1223         list_splice_init(&tdc->pending_sg_req, &sg_req_list);
1224         list_splice_init(&tdc->free_sg_req, &sg_req_list);
1225         list_splice_init(&tdc->free_dma_desc, &dma_desc_list);
1226         INIT_LIST_HEAD(&tdc->cb_desc);
1227         tdc->config_init = false;
1228         tdc->isr_handler = NULL;
1229         spin_unlock_irqrestore(&tdc->lock, flags);
1230
1231         while (!list_empty(&dma_desc_list)) {
1232                 dma_desc = list_first_entry(&dma_desc_list,
1233                                         typeof(*dma_desc), node);
1234                 list_del(&dma_desc->node);
1235                 kfree(dma_desc);
1236         }
1237
1238         while (!list_empty(&sg_req_list)) {
1239                 sg_req = list_first_entry(&sg_req_list, typeof(*sg_req), node);
1240                 list_del(&sg_req->node);
1241                 kfree(sg_req);
1242         }
1243         pm_runtime_put(tdma->dev);
1244
1245         tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
1246 }
1247
1248 static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
1249                                            struct of_dma *ofdma)
1250 {
1251         struct tegra_dma *tdma = ofdma->of_dma_data;
1252         struct dma_chan *chan;
1253         struct tegra_dma_channel *tdc;
1254
1255         if (dma_spec->args[0] > TEGRA_APBDMA_CSR_REQ_SEL_MASK) {
1256                 dev_err(tdma->dev, "Invalid slave id: %d\n", dma_spec->args[0]);
1257                 return NULL;
1258         }
1259
1260         chan = dma_get_any_slave_channel(&tdma->dma_dev);
1261         if (!chan)
1262                 return NULL;
1263
1264         tdc = to_tegra_dma_chan(chan);
1265         tdc->slave_id = dma_spec->args[0];
1266
1267         return chan;
1268 }
1269
1270 /* Tegra20 specific DMA controller information */
1271 static const struct tegra_dma_chip_data tegra20_dma_chip_data = {
1272         .nr_channels            = 16,
1273         .channel_reg_size       = 0x20,
1274         .max_dma_count          = 1024UL * 64,
1275         .support_channel_pause  = false,
1276         .support_separate_wcount_reg = false,
1277 };
1278
1279 /* Tegra30 specific DMA controller information */
1280 static const struct tegra_dma_chip_data tegra30_dma_chip_data = {
1281         .nr_channels            = 32,
1282         .channel_reg_size       = 0x20,
1283         .max_dma_count          = 1024UL * 64,
1284         .support_channel_pause  = false,
1285         .support_separate_wcount_reg = false,
1286 };
1287
1288 /* Tegra114 specific DMA controller information */
1289 static const struct tegra_dma_chip_data tegra114_dma_chip_data = {
1290         .nr_channels            = 32,
1291         .channel_reg_size       = 0x20,
1292         .max_dma_count          = 1024UL * 64,
1293         .support_channel_pause  = true,
1294         .support_separate_wcount_reg = false,
1295 };
1296
1297 /* Tegra148 specific DMA controller information */
1298 static const struct tegra_dma_chip_data tegra148_dma_chip_data = {
1299         .nr_channels            = 32,
1300         .channel_reg_size       = 0x40,
1301         .max_dma_count          = 1024UL * 64,
1302         .support_channel_pause  = true,
1303         .support_separate_wcount_reg = true,
1304 };
1305
1306 static int tegra_dma_probe(struct platform_device *pdev)
1307 {
1308         struct resource *res;
1309         struct tegra_dma *tdma;
1310         int ret;
1311         int i;
1312         const struct tegra_dma_chip_data *cdata;
1313
1314         cdata = of_device_get_match_data(&pdev->dev);
1315         if (!cdata) {
1316                 dev_err(&pdev->dev, "Error: No device match data found\n");
1317                 return -ENODEV;
1318         }
1319
1320         tdma = devm_kzalloc(&pdev->dev, sizeof(*tdma) + cdata->nr_channels *
1321                         sizeof(struct tegra_dma_channel), GFP_KERNEL);
1322         if (!tdma) {
1323                 dev_err(&pdev->dev, "Error: memory allocation failed\n");
1324                 return -ENOMEM;
1325         }
1326
1327         tdma->dev = &pdev->dev;
1328         tdma->chip_data = cdata;
1329         platform_set_drvdata(pdev, tdma);
1330
1331         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1332         tdma->base_addr = devm_ioremap_resource(&pdev->dev, res);
1333         if (IS_ERR(tdma->base_addr))
1334                 return PTR_ERR(tdma->base_addr);
1335
1336         tdma->dma_clk = devm_clk_get(&pdev->dev, NULL);
1337         if (IS_ERR(tdma->dma_clk)) {
1338                 dev_err(&pdev->dev, "Error: Missing controller clock\n");
1339                 return PTR_ERR(tdma->dma_clk);
1340         }
1341
1342         tdma->rst = devm_reset_control_get(&pdev->dev, "dma");
1343         if (IS_ERR(tdma->rst)) {
1344                 dev_err(&pdev->dev, "Error: Missing reset\n");
1345                 return PTR_ERR(tdma->rst);
1346         }
1347
1348         spin_lock_init(&tdma->global_lock);
1349
1350         pm_runtime_enable(&pdev->dev);
1351         if (!pm_runtime_enabled(&pdev->dev))
1352                 ret = tegra_dma_runtime_resume(&pdev->dev);
1353         else
1354                 ret = pm_runtime_get_sync(&pdev->dev);
1355
1356         if (ret < 0) {
1357                 pm_runtime_disable(&pdev->dev);
1358                 return ret;
1359         }
1360
1361         /* Reset DMA controller */
1362         reset_control_assert(tdma->rst);
1363         udelay(2);
1364         reset_control_deassert(tdma->rst);
1365
1366         /* Enable global DMA registers */
1367         tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
1368         tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
1369         tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
1370
1371         pm_runtime_put(&pdev->dev);
1372
1373         INIT_LIST_HEAD(&tdma->dma_dev.channels);
1374         for (i = 0; i < cdata->nr_channels; i++) {
1375                 struct tegra_dma_channel *tdc = &tdma->channels[i];
1376
1377                 tdc->chan_addr = tdma->base_addr +
1378                                  TEGRA_APBDMA_CHANNEL_BASE_ADD_OFFSET +
1379                                  (i * cdata->channel_reg_size);
1380
1381                 res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
1382                 if (!res) {
1383                         ret = -EINVAL;
1384                         dev_err(&pdev->dev, "No irq resource for chan %d\n", i);
1385                         goto err_irq;
1386                 }
1387                 tdc->irq = res->start;
1388                 snprintf(tdc->name, sizeof(tdc->name), "apbdma.%d", i);
1389                 ret = request_irq(tdc->irq, tegra_dma_isr, 0, tdc->name, tdc);
1390                 if (ret) {
1391                         dev_err(&pdev->dev,
1392                                 "request_irq failed with err %d channel %d\n",
1393                                 ret, i);
1394                         goto err_irq;
1395                 }
1396
1397                 tdc->dma_chan.device = &tdma->dma_dev;
1398                 dma_cookie_init(&tdc->dma_chan);
1399                 list_add_tail(&tdc->dma_chan.device_node,
1400                                 &tdma->dma_dev.channels);
1401                 tdc->tdma = tdma;
1402                 tdc->id = i;
1403                 tdc->slave_id = TEGRA_APBDMA_SLAVE_ID_INVALID;
1404
1405                 tasklet_init(&tdc->tasklet, tegra_dma_tasklet,
1406                                 (unsigned long)tdc);
1407                 spin_lock_init(&tdc->lock);
1408
1409                 INIT_LIST_HEAD(&tdc->pending_sg_req);
1410                 INIT_LIST_HEAD(&tdc->free_sg_req);
1411                 INIT_LIST_HEAD(&tdc->free_dma_desc);
1412                 INIT_LIST_HEAD(&tdc->cb_desc);
1413         }
1414
1415         dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
1416         dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
1417         dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);
1418
1419         tdma->global_pause_count = 0;
1420         tdma->dma_dev.dev = &pdev->dev;
1421         tdma->dma_dev.device_alloc_chan_resources =
1422                                         tegra_dma_alloc_chan_resources;
1423         tdma->dma_dev.device_free_chan_resources =
1424                                         tegra_dma_free_chan_resources;
1425         tdma->dma_dev.device_prep_slave_sg = tegra_dma_prep_slave_sg;
1426         tdma->dma_dev.device_prep_dma_cyclic = tegra_dma_prep_dma_cyclic;
1427         tdma->dma_dev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1428                 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1429                 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1430                 BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1431         tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |
1432                 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |
1433                 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) |
1434                 BIT(DMA_SLAVE_BUSWIDTH_8_BYTES);
1435         tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
1436         /*
1437          * XXX The hardware appears to support
1438          * DMA_RESIDUE_GRANULARITY_BURST-level reporting, but it's
1439          * only used by this driver during tegra_dma_terminate_all()
1440          */
1441         tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
1442         tdma->dma_dev.device_config = tegra_dma_slave_config;
1443         tdma->dma_dev.device_terminate_all = tegra_dma_terminate_all;
1444         tdma->dma_dev.device_tx_status = tegra_dma_tx_status;
1445         tdma->dma_dev.device_issue_pending = tegra_dma_issue_pending;
1446
1447         ret = dma_async_device_register(&tdma->dma_dev);
1448         if (ret < 0) {
1449                 dev_err(&pdev->dev,
1450                         "Tegra20 APB DMA driver registration failed %d\n", ret);
1451                 goto err_irq;
1452         }
1453
1454         ret = of_dma_controller_register(pdev->dev.of_node,
1455                                          tegra_dma_of_xlate, tdma);
1456         if (ret < 0) {
1457                 dev_err(&pdev->dev,
1458                         "Tegra20 APB DMA OF registration failed %d\n", ret);
1459                 goto err_unregister_dma_dev;
1460         }
1461
1462         dev_info(&pdev->dev, "Tegra20 APB DMA driver register %d channels\n",
1463                         cdata->nr_channels);
1464         return 0;
1465
1466 err_unregister_dma_dev:
1467         dma_async_device_unregister(&tdma->dma_dev);
1468 err_irq:
1469         while (--i >= 0) {
1470                 struct tegra_dma_channel *tdc = &tdma->channels[i];
1471
1472                 free_irq(tdc->irq, tdc);
1473                 tasklet_kill(&tdc->tasklet);
1474         }
1475
1476         pm_runtime_disable(&pdev->dev);
1477         if (!pm_runtime_status_suspended(&pdev->dev))
1478                 tegra_dma_runtime_suspend(&pdev->dev);
1479         return ret;
1480 }
1481
1482 static int tegra_dma_remove(struct platform_device *pdev)
1483 {
1484         struct tegra_dma *tdma = platform_get_drvdata(pdev);
1485         int i;
1486         struct tegra_dma_channel *tdc;
1487
1488         dma_async_device_unregister(&tdma->dma_dev);
1489
1490         for (i = 0; i < tdma->chip_data->nr_channels; ++i) {
1491                 tdc = &tdma->channels[i];
1492                 free_irq(tdc->irq, tdc);
1493                 tasklet_kill(&tdc->tasklet);
1494         }
1495
1496         pm_runtime_disable(&pdev->dev);
1497         if (!pm_runtime_status_suspended(&pdev->dev))
1498                 tegra_dma_runtime_suspend(&pdev->dev);
1499
1500         return 0;
1501 }
1502
1503 static int tegra_dma_runtime_suspend(struct device *dev)
1504 {
1505         struct tegra_dma *tdma = dev_get_drvdata(dev);
1506
1507         clk_disable_unprepare(tdma->dma_clk);
1508         return 0;
1509 }
1510
1511 static int tegra_dma_runtime_resume(struct device *dev)
1512 {
1513         struct tegra_dma *tdma = dev_get_drvdata(dev);
1514         int ret;
1515
1516         ret = clk_prepare_enable(tdma->dma_clk);
1517         if (ret < 0) {
1518                 dev_err(dev, "clk_enable failed: %d\n", ret);
1519                 return ret;
1520         }
1521         return 0;
1522 }
1523
1524 #ifdef CONFIG_PM_SLEEP
1525 static int tegra_dma_pm_suspend(struct device *dev)
1526 {
1527         struct tegra_dma *tdma = dev_get_drvdata(dev);
1528         int i;
1529         int ret;
1530
1531         /* Enable clock before accessing register */
1532         ret = pm_runtime_get_sync(dev);
1533         if (ret < 0)
1534                 return ret;
1535
1536         tdma->reg_gen = tdma_read(tdma, TEGRA_APBDMA_GENERAL);
1537         for (i = 0; i < tdma->chip_data->nr_channels; i++) {
1538                 struct tegra_dma_channel *tdc = &tdma->channels[i];
1539                 struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
1540
1541                 /* Only save the state of DMA channels that are in use */
1542                 if (!tdc->config_init)
1543                         continue;
1544
1545                 ch_reg->csr = tdc_read(tdc, TEGRA_APBDMA_CHAN_CSR);
1546                 ch_reg->ahb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBPTR);
1547                 ch_reg->apb_ptr = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBPTR);
1548                 ch_reg->ahb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_AHBSEQ);
1549                 ch_reg->apb_seq = tdc_read(tdc, TEGRA_APBDMA_CHAN_APBSEQ);
1550                 if (tdma->chip_data->support_separate_wcount_reg)
1551                         ch_reg->wcount = tdc_read(tdc,
1552                                                   TEGRA_APBDMA_CHAN_WCOUNT);
1553         }
1554
1555         /* Disable clock */
1556         pm_runtime_put(dev);
1557         return 0;
1558 }
1559
1560 static int tegra_dma_pm_resume(struct device *dev)
1561 {
1562         struct tegra_dma *tdma = dev_get_drvdata(dev);
1563         int i;
1564         int ret;
1565
1566         /* Enable clock before accessing register */
1567         ret = pm_runtime_get_sync(dev);
1568         if (ret < 0)
1569                 return ret;
1570
1571         tdma_write(tdma, TEGRA_APBDMA_GENERAL, tdma->reg_gen);
1572         tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
1573         tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFFul);
1574
1575         for (i = 0; i < tdma->chip_data->nr_channels; i++) {
1576                 struct tegra_dma_channel *tdc = &tdma->channels[i];
1577                 struct tegra_dma_channel_regs *ch_reg = &tdc->channel_reg;
1578
1579                 /* Only restore the state of DMA channels that are in use */
1580                 if (!tdc->config_init)
1581                         continue;
1582
1583                 if (tdma->chip_data->support_separate_wcount_reg)
1584                         tdc_write(tdc, TEGRA_APBDMA_CHAN_WCOUNT,
1585                                   ch_reg->wcount);
1586                 tdc_write(tdc, TEGRA_APBDMA_CHAN_APBSEQ, ch_reg->apb_seq);
1587                 tdc_write(tdc, TEGRA_APBDMA_CHAN_APBPTR, ch_reg->apb_ptr);
1588                 tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBSEQ, ch_reg->ahb_seq);
1589                 tdc_write(tdc, TEGRA_APBDMA_CHAN_AHBPTR, ch_reg->ahb_ptr);
1590                 tdc_write(tdc, TEGRA_APBDMA_CHAN_CSR,
1591                         (ch_reg->csr & ~TEGRA_APBDMA_CSR_ENB));
1592         }
1593
1594         /* Disable clock */
1595         pm_runtime_put(dev);
1596         return 0;
1597 }
1598 #endif
1599
1600 static const struct dev_pm_ops tegra_dma_dev_pm_ops = {
1601         SET_RUNTIME_PM_OPS(tegra_dma_runtime_suspend, tegra_dma_runtime_resume,
1602                            NULL)
1603         SET_SYSTEM_SLEEP_PM_OPS(tegra_dma_pm_suspend, tegra_dma_pm_resume)
1604 };
1605
1606 static const struct of_device_id tegra_dma_of_match[] = {
1607         {
1608                 .compatible = "nvidia,tegra148-apbdma",
1609                 .data = &tegra148_dma_chip_data,
1610         }, {
1611                 .compatible = "nvidia,tegra114-apbdma",
1612                 .data = &tegra114_dma_chip_data,
1613         }, {
1614                 .compatible = "nvidia,tegra30-apbdma",
1615                 .data = &tegra30_dma_chip_data,
1616         }, {
1617                 .compatible = "nvidia,tegra20-apbdma",
1618                 .data = &tegra20_dma_chip_data,
1619         }, {
1620         },
1621 };
1622 MODULE_DEVICE_TABLE(of, tegra_dma_of_match);
1623
1624 static struct platform_driver tegra_dmac_driver = {
1625         .driver = {
1626                 .name   = "tegra-apbdma",
1627                 .pm     = &tegra_dma_dev_pm_ops,
1628                 .of_match_table = tegra_dma_of_match,
1629         },
1630         .probe          = tegra_dma_probe,
1631         .remove         = tegra_dma_remove,
1632 };
1633
1634 module_platform_driver(tegra_dmac_driver);
1635
1636 MODULE_ALIAS("platform:tegra20-apbdma");
1637 MODULE_DESCRIPTION("NVIDIA Tegra APB DMA Controller driver");
1638 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1639 MODULE_LICENSE("GPL v2");